There are many applications where it is desirable to initiate a chemical reaction on a sample. Commonly the samples are located on a microscope slide. Typical reactions include immuno-histochemical reactions of cellular material, or in situ-hybridisation of DNA or RNA. In other forms, microarrays of thousands of small samples of material, including DNA, RNA proteins or small chemical compounds are attached to a microscope slide, where it is desirable to promote a chemical reaction between the material on the slide and other chemicals or fluids. These reactions require controlled conditions, including controlled reaction time, temperature and concentration of chemicals.
In the past, chemical reactions taking place on slides were controlled by skilled persons adding and mixing the reagents. This allowed the time and quantity of the reagents to be controlled for each slide. However, this procedure was time consuming, required highly skilled operators, and could produce inconsistent results from slide to slide.
Attempts have been made to automatically treat tissue samples disposed on slides for immunologic applications using, for example, an automated tissue sample staining apparatus. In this example, the automated staining apparatus treats tissue samples using reagents to treat the sample before staining the samples on the slides. The treatment of the samples is typically performed automatically by one or more robots configured to dispense reagents to the samples on the slides in a predetermined sequence according to a staining protocol. In addition, the robots can also be configured to dispense reagents such as dewaxing solution and alcohol to treat the samples on slides before and after staining. The reagent currently being dispensed by one of the robots, however, must be purged from the robots before other reagents can be dispensed causing delay, reagent wastage and inefficient use of the automated staining apparatus.
In spite of these advances, existing tissue sample treatment methods comprise a number of steps that are performed manually. For example, in immunologic applications, such as in-situ hybridization (ISH) and immunohistochemical (IHC) applications, some steps including dewaxing and target retrieval are performed manually by an operator to treat the tissue sample before it can be used in a staining apparatus for staining the tissue sample according to a predetermined staining protocol.
It would be desirable to provide an apparatus for treating biological samples disposed on substrates which minimises the manual labour required to treat the samples. Moreover, there exists a need to provide such an apparatus which treats biological samples in a simple, time-efficient manner. There also exists a need to provide an apparatus for treating biological samples disposed on substrates which ameliorates and/or overcomes disadvantages or inconveniences of known automatically sample treatment apparatuses.
The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.